Core A - Core Summary: This application constitutes a request for continuation of a Tropical Medicine Research Center that was awarded to Banaras Hindu University in Varanasi, India in 2007 and 2012. Participating investigators form a multi-national network of collaborating scientists studying critical aspects of the fatal disease, visceral leishmaniasis, in Bihar State, India. This region has the highest endemic rate of visceral leishmaniasis in India, and one of the highest rates of visceral leishmaniasis worldwide. The renewed program will build on the substantial foundation set up in the first TMRC program, including entry of 111,999 subjects from the state of Bihar into a substantial epidemiological survey. The considerable progress made in understanding the epidemiologic, genetic and immune risks for visceral leishmaniasis have formed the hypotheses upon which this renewed application is built. The program will include one scientific core, a Health Demographic Surveillance System. Three projects are proposed: (1) Human epidemiology in the context of the VL elimination initiative, (2) Vector Biological Studies, (3) Immune regulation in human VL. The program will be coordinated at Banaras Hindu University, through the efforts of the Administrative Core and the Data Management and Biostatistics Core. Specific aims of the program are: 1. To provide administrative coordination of the one scientific core, the three research projects and the Data Management & Biostatistics core of the TMRC program. This will include communication with collaborating investigators at institutions within and outside of India, communication with NIH personnel, and assurance of compliance with NIH requirements. 2. To provide financial accounting and oversight of finances at BHU, KAMRC in Muzaffarpur, Institute of Tropical Medicine, Belgium, QIMR Berghofer Medical Research Institute, Herston, Australia and the University of Iowa, USA. This will include distribution of funds, payment of salaries and overall accounting of expenses. 3. To perform the day to day management of the projects. This will involve purchase and distribution of equipment and research supplies, management of personnel, coordination of publications, and arranging communication between investigators on specific projects. 4. To coordinate meetings and training activities. Key activities are (A) the annual TMRC meeting in Varanasi, India, which is attended by participating TMRC scientists and administrators from BHU and Muzaffarpur, and by collaborating investigators from other universities in India, the USA, Australia and Belgium; (B) travel and housing for Indian investigators to participate in scientific meetings, short courses, or short term training experiences in labs at collaborating universities.